Thames Landscape Strategy - Hampton to Kew -

Arcadian Diary May 2005

The link between human activity and global warming is still not conclusively proven, but what is now universally accepted is that climates are changing, and changing faster than at any time in human history. What remains unclear is the pace of the change, what is causing this change, and the exact effects of this shift on the world’s climate. What is certain, however, is the need to plan for climate change as we begin to realise just how our everyday lives will be affected.

A large, low lying city like London is particularly sensitive to climate change. In response a special group – The London Climate Change Partnership, has been set up to identify what the effects of climate change could be to the capital, and the group’s findings will have an impact on planning the future of the city.

Of particular concern is the affect of anticipated temperature rise due to the ‘urban heat island’ effect that London is especially vulnerable to. Research has shown that both summer heat island intensity and frequency are increasing as climate changes. The most noticeable and uncomfortable effect of this would be on night time temperatures. Hotter, drier summers might be great for the tourism industry and kids on their school holidays, but will have detrimental effects on water resources and air quality. Rising temperatures will increase the need for air conditioning inside buildings, tubes and buses simply adding to the problem due to increased use of fuels to generate the electricity. It is true that a reduction in the need to heat property would offset this slightly, but it is looking increasingly likely that a fundamental new approach in the way that buildings are designed (and where they should be built) is going to be needed. By the middle of this century summer temperatures of 30C could be the norm with London having a climate similar to that of New York, Rome or Madrid of today.

It may be hard to imagine, but London is officially one of the world’s driest capital cities. In fact the available water resources per head of population are similar to that of Israel. It is now anticipated that climate change will have a big impact on rainfall with drier summers, wetter winters and increased flash storms. Long periods of snowfall are now a distant memory and in many winters the incidence of night frosts can be counted on one hand. The effects of this are varied. Whilst a summer ban on hose pipes by 2050 would be inconvenient, it could be said that warmer, drier summers would stimulate an al fresco lifestyle. However, it is the effects of climate change on the environment around us that is worrying most people, and in particular the effect of climate change on flooding and the capital’s wildlife.

The need to protect London against a predicted increase in flood risk is now a number one priority even though London has some of the best flood management measures in the world due to the fact that a lot of the metropolis lies within the floodplain of the River Thames. The future risk from flooding is made worse for three reasons. Current levels of defence do not take into account increased river flows and storm runoff caused by climate change (20% more storm water for example will pass over Teddington Weir and into the Thames estuary by 2050), the pressure to build in the floodplain is increasing (resulting in less land available to absorb the flood waters) and sea levels are rising (reducing the impact of existing defences and the impact of North Sea storm surges).

Research into the flood risk implications for London is being co-ordinated by the Environment Agency through their ‘Thames Estuary Flood Management Strategy (TE2100). Locally, the ‘Floodscape’ study (part of a wider European initiative led by the Environment Agency) has looked at the effect of what would happen if Ham Lands was managed in a way that it could once again function as water meadows allowing the area to be used as a storage area for the vital few hours of peak floods, when high river flows and storm surge tides converge below Teddington Lock.

Climate change will also have an effect on wildlife. Earlier springs, longer frost free seasons, and reduced snowfall would affect the bird nesting season and the dates that trees come into leaf are getting earlier and earlier. Valuable habitats may be lost or degraded due to lack of water or changes in temperature, and an increase in pests, diseases and invasive species could have a negative impact on established flora and fauna. The Chinese mitten crab for example (one of the most destructive invasive species in the UK), is already prolific in our part of the Thames and is destroying one of the most valuable riverside habitats alongside Syon Park and has recently been reported in the Hogsmill River.

Shifts in the world’s climate may not necessarily be bad for all wildlife, but what is certain is that some established ecosystems will change, and habitats that we cherish today may be lost in the future. Difficult choices will need to be made in terms of land management, and we may find ourselves committed to protecting certain habitats and species that will struggle to adapt to a new climate. In other places new environments will emerge, and species that are rare today may become much more common.

Climate change is going to affect all of us – to what extent is still to be established and a hotly debated subject. However, it is certain that as climate changes the public open spaces along the Thames will become increasingly important to Londoners – how much these places will have to adapt is unclear.

For more information on the proposed Floodscape project visit www.floodscape.net

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